Gear testing and recording machine



June 9, 1942. o. J. POUPITCH GEAR TESTING AND RECORDING MACHINE Original Filed Sept. 1, 1938 6 Sheets-Sheet 1 INVENTOR. J a'a/J'Hasfigmtah [Trl ATTORNEY$ June 9, 1942. o. J. POUPITCH R 22, 10

GEAR TESTING AND RECORDING MACHINE 'Orizinal Filed Sept. 1, 1938 6 Sheets-Sheet 2 "j 8 INVENTOR. S Q 10 519i e50 Jaks Q fiqpzic/z 6 Sheets-Sheet 4 INVENTOR. aksflgmid ATTORNEYS June 9, 1942. o. J. POUPITCH GEAR TESTING AND RECORDING MACHINE Original Filed Sept. 1, 1938 0 1HH I w 4 N J IH I q 0 niimliili- 11 8 fix 0 w; 6 a 7 m a z x m y B J -1 i m 1|| 1) v fi v H a i i m w A x I Ill 6 a u 7 m I \w 0 a. L w i j y, a a

June 9. 1942. o, ouprrc Re. 22,110

GEAR TESTING AND RECORDING MACHINE Original Filed Sept. 1, 1958 6 Sheets-Sheet 5 /G- 17 INVENTOR; 0z gjesa Jaksflgw'zch BY: 2 z

oooooooooooooooooooo ATTORNEYS June'9, 1942. Q J PQUPITCH Re. 22,110

GEAR TESTING AND RECORDING MACHINE Original Filed Sept. 1, 1938 6 Sheets-Sheet 6 I AM INVENTOR.

ATTORNEYS Reiseuerl June 9, 1942 GEAR TESTING AND RECORDING MACHINE Ougljesa Jules Poupitch, Chicago, Ill., assignor to Illinois Tool Works, Chicago, 111., a corporation of Illinois Original No. 2,200,853, dated July 2, 1940, Serial No. 227,944, September 1, 1938. Application for reissue July 1, 1941, Serial No. 400,698

13 Claims.

This invention relates to an involute test and recorder.

It is an object of this invention to provide a compact, inexpensive, efficient and highly sensitive involute tester and recorder capable of use without special instruction or training and providing means by which the accuracy of the data taken shall be independent of the skill or lacln of skill of the operator making the test.

Another object is to provide a tester and recorder of the above stated character in which means are provided for controlling the feeding movement of a record sheet by the movement of the testing instrumentality and simultaneously therewith, said means being so designed as to eilect the feeding of the record sheet in the same direction independent of the direction of movement of the testing instrumentality.

Appllcants invention further contemplates the provision of an electro-optical, involute tester and recorder embodying ray-controlling means operable in response to the minutest deflection of the work piece from the involute curve to effect an accurately proportioned variation in the quantum of rays falling upon a ray sensitive electric cell.

A more specific object is to provide in such an electro-optical, involute tester and recorder complementary arcuate ray controlling screens, grids or gratings relatively adiustable in a simple and expeditious manner to determine the zero or midpoint of the tester and the base line or abscissa of the recorded curve, at least one of these screens being mounted for a substantially frictionless deflection in response to a deviation of the work piece from the involute curve and the other screen being mutually concentric with the first screen to the point origin of the rays so that upon deflection every unit area of the ray beam passing through the screens will be equally varied and this variation will be precisely proportioned to the amount of deviation of the work piece from the involute curve.

A further object of the invention is to provide a testing or control unit that may be used for recording instruments of various types such, for example, as for testing hobs and gears and for any other purpose for which the relatively swinging arcuate screens may be functionally adapted, such as for the remote control of airplanes, ships and the like, and/as part of height and depth measuring instruments.

Other objects and advantages will be apparent from the following detailed description when considered in connection with the accompanying drawings wherein:

Fig. 1 is a view in perspective of an involute testing and recording machine which is representative of one embodiment of the invention.

Fig. 2 is a vertical section taken substantially along the line 2-2 of Fig. 1.

Fig. 3 is a fragmentary view in horizontal section along the line 8-3 of Fig. 2.

Fig. 4 is a fragmentary horizontal section taken along the line l-l of Fig. 2.

Fig. 5 is a fragmentary view in vertical section taken along the line 55 of Fig. 4.

Fig. 6 is a fragmentary vertical section taken along the line 8-6 of Fig. 2.

Fig. 7 is a fragmentary vertical section taken along the line 'l-I of Fig. 4.

Fig. 8 is a fragmentary vertical section along the line B8 of Fig. 6.

Fig. 9 is a fragmentary horizontal section along the line 9-9 of Fig. 8.

Fig. 10 is a fragmentary horizontal section along the line lllili of Fig. 6.

Fig. 11 is a fragmentary vertical section through the recorder taken along the line il--li of Fig. l.

Fig. 12 is a fragmentary vertical section taken along the line i2-I2 of Fig. 11.

Fig. 13 is a fragmentary horizontal section through a portion of the mechanism connecting the recorder to the tester head and is taken along the line i3-I3 of Fig. 1.

Fig. 14 is a fragmentary view in elevation and partly in section taken along the line il-H of Fig. 13.

Fig. 15 is a fragmentary horizontal section along the line i5l5 of Fig. 11.

Fig. 16 is a detail perspective view of a portion of the record sheet drive means.

Fig. 1'7 is an illustrative view of a record sheet provided by the machine of the invention.

Fig. 18 is a diagrammative illustration of the ray controlling members.

Referring now to the drawings more in detail, it will be seen that a machine forming one embodiment of the invention includes a suitable base 20. Mounted upon the upper portion of the base 20 is a slide frame 22. This frame 22 is slidable upon horizontal ways or tracks 24 provided along the upper edge of the base 20 (Fig. 2). The frame 22 is formed with a depending section 26 in which is journaled a sleeve 20, the sleeve 28 being retained between frictionless bearings 36. A sleeve 32 is journaled in the bearings 30 and the sleeve 28, and the sleeve 32 is provided at its upper end with an enlarged portion retaining the upper bearing 30 in position and at its lower end receives a nut 34 which retains the lower bearing in position.

The sleeve 32 receives the tapered shank 36 of a spindle 38, which spindle is provided with an annular flange 40 which forms a support for a cylindrical member, ring or disk 42 which is of an external diameter equal to the diameter of the base circle of a gear 44 to be tested. The

disk 42 therefore constitutes in effect a base cylinder for the gear to be tested and is accordingly detachably mounted on the spindle 38 so that it may be readily replaced by a similar disk of different size corresponding to a different size gear to be tested. The spindle 38 is therefore threaded as at 45 adjacent its upper end to receive a clamping nut 30 by which the disk is retained in position on a supporting flange 0.

The spindle 33 terminates at its upper end in a conical work supporting center 50, which receives the lower end of the gear or work supporting spindle 52. The upper end of the spindle 52 is received by the center 53 (Fig. 1) which is carried by its tailstock 50, which taiistock includes a housing 53 for the spindle which supports the center 53 and a pairof diverging arms which terminate in sleeves 00. These sleeves are siidable upon vertical posts or columns 02 and are adjustable vertically of the columns by a hand-wheel which controls a gear having meshing engagement with the rack teeth 88 (Fig. 2) formed on one or both of the columns 52. The center 55 is adjustable with the spindle and relative to the housing 53 in a similar manner by means of a hand-wheel 60. The columns 52 are carried by the frame 22.

The base cylinder 42 is coupled to the gear 44 to be tested by a lever 10 which is detachably clamped to the spindle 88 in any suitable conventional manner and the arm of this lever is slotted as at I2 to receive a post or rod II, which, in any suitable manner, is clamped to the lever for adjustment along the slot 12. The post I4 supports for vertical adjustment relative thereto a pin or rod 13 which may be clamped on the post I3 by means of a set screw I5 carried by the supporting yoke for the pin I5. The pin I0 projects between adjacent teeth of the gear to betestedasshowninFig. l.

The base cylinder retaining nut 45 in clamping the base cylinder on the spindle 38 also couples the spindle and cylinder for simultaneous rotation and hence the rotation of the base cylinder will be imparted to the gear to be tested through the nut 43, the spindle 30, the lever 10, the post I4 and the pin I3.

A supporting frame 00 for a testing instrumentality or device 32 is slidably mounted upon the front end of the base 20. The frame is provided with a depending portion 83 to which is secured at its lower end a roller bearing 33 which mils along the flat surface of a plate or bar 53 secured to the base 20. A similar roller bearing 00 is secured to the upper portion of the frame 33 and this bearing rolls along the forward surface of a bar 52 secured to the upper edge of the base 20. The frame 30 is additionally formed with a rearwardly extending portion or section 5| overlying the bar 52 and extending downwardly behind the same. In its downward extension the section 04 carries a bar 35 inhorizontal alinement with the bar 32 and between this bar 33 and the bar 32 are interposed a plurality of antifriction ball bearings.

- A bar I00 is secured to the section "of the frame 30 and is provided with a friction surface to engage the peripheral surface of the base cylinder 32 and accordingly when the'bar I00 is moved horizontally with the frame 30 rotation is imparted to the base cylinder 42.

- The frame 30 is moved horizontally by means of ahandwheel I02 (Fig. l) which controls a system of gears. (not shown), the end gear of provided along the underside of the stationary bar 32.

An auxiliary frame I06 forms part of the frame and is slidably mounted in suitable ways formed on the downward extension 04 (Figs. 1 and 2). Vertical adjustment of the auxiliary frame I08 is accomplished by a handwheel I08 which controls the rotation of a gear IIO which in turn meshes with rack teeth (not shown) formed on the downward extension 04 of the frame 80.

The testing instrumentality or device 02 is secured to the upper end of the auxiliary frame or slide I06. This instrumentality comprises a contactor II2 adjustably mounted in a block or tube I and retained in adjusted position thereinby a set screw IIS (Figs. 4 and 5). The contactor H2 is adapted to engage the involute toothed surfaces of a gear to be tested at the point of intersection of the,base circle with the toothed surfaces and is adapted to control the deflection of a ray controlling member or means H8. The latter member or means comprises a lamp receiving housing formed by an inclined top wall I20, a substantially horizontal wall I22, diverging side walls I24 and I25 and an end wall I20 formed integrally with a mounting boss I30 (Figs. 4 and 5).

The lamp receiving housing is open at one end and this end is arcuate in cross section (as seen in Fig. 4) the side and bottom walls forming at this end of the housing a frame to receive an arcuate ray controlling grid. grating screen or the like I32. The screen I32 preferablyjl comprises a sector of plate glass etched on its outer surface with lines .001 of an inch in width spaced .001 of an inch apart, a The screen, grid or grating I32 cooperates with a similar arcuate screen, grid or grating I33 mounted in a frame I35, the screen I35 being preferably formed from a piece of plate glass etched on its inner surface with lines of the same width and.

spacing as the lines on the screen I32.

The mounting boss I30 for the ray controlling member or means III is apertured to receive a pivot pin or stud I33 and to receive the block or tube III. The block Ill is secured to the boss I30asbyascrew I30 andthebossissecuredto the stud I38 as by set screws I32. The stud I33 is mounted between adjustable centers I and I36. The center I is adjustabiy mounted within a sleeve I33 secured to the horizontally extending arm I50 of a bracket I52 having spaced vertically extending arms I55, the bracket I52 being formed integrally with or secured to the auxiliary frame I05. The center I13 is adjustably mounted ina sleeve I55 secured to the base of the bracket I52.

The arcuate screens I32 and I33 are preferably concentric to the axis of the pivot stud I33 so that as the contactor II2 is deflected in response to the deviations of. a toothed surface from the true involute curve 'the screens I32 and I34 will cooperate to vary the amount of light passed therethrough in strict proportionality to the deflection of the contactor.

The screen I32 is preferably mounted in the frame formed by the outer end of the lamp housing II! by a dovetail fit therein and is preferably resiliently held therein by a spring, catch orthelike I5lsecuredtoasidewaliofthelamp housing and passing through a longitudinally extending opening in the frame defining portion of the housing into engagement with an edge of which meshes with the'rack teeth I33 (Fig. 2) t5 the screen I32. Accordingly, any looseness in the fit of the screen I32 is compensated by the spring I58.

A housing or casting I60 is provided for the ray controlling member. or means "8. This housing is provided with forwardly extending side walls I62 which inclose the lamp housing II9, and forwardly extending top and bottom walls which are apertured to receive the centers I44 and I46 so that the housing I60 is pivotally supported for adjustment relative to the contactor H2 and the screen I32 about the coincident pivot axis of said contactor and said screen.

A lamp or ray source I68 is mounted upon the top wall of the housing I60 and extends into the lamp housing II9 through an enlarged opening in the top wall I20 of this housing I III. The lamp I68 is received within a socket I10 which preferably comprises (as best shown in Figs. 8 and 9) an insulating cylinder I12 having secured internally thereof a screw threaded contact shell I14, the shell I14 carrying a contact button I16 which is insulated from the shell and positioned to engage the central contact projection of the lamp.

The insulating cylinder I12 is provided with contact rings I18 and I80 recessed into the outer surface thereof, the contact ring I18 being connected to the contact button I16 by a suitable wire and the contact ring I80 being connected to the shell I14 by a pin or the like I82 passing through the cylinder I12. The insulating cylinder I12 is secured to an insulating block I64 which in turn is secured as by screws I86 to the top wall of the housing I60. The insulating block I84 is provided with wire receiving terminals or screws I88 (Fig. 9) which in turn are connected to the contact rings I18 and I80 by resilient contact blades I90 engaging the outer ends of metal plungers I92 mounted in the insulating block I84 and engaging at their inner ends the contact rings I18 and I60.

It will be seen from Figs. 8 and 9 that the insulating cylinder I12 together with the lamp I68 may be readily removed from the housings H9 and I60 by pulling upwardly upon a flanged knob I93 (Fig. 5). It should also be noted that the internal surface of the end wall I28 of the housing H9 is, in any suitable manner, made light reflecting in character so as to direct the rays of light from the lamp I58 by reflection upon the screen I82.

An electro-optical cell I94 (Figs. 4 and 5) is mounted within the housing I60 between the mounting frame I36 for the screen I34 and a retaining frame I96 secured to the rear wall of the by a sleeve 204 (Fig. 7) in a boss 206 formed on the housing I80. The stud 202 is provided at its upper end with an adjusting knob 208 secured thereto and at its lower end is provided with an eccentric pin 2I0. The eccentric pin 2I0 is recelved within a slot 2I2 (Fig. 10) in a fixed plate 2I4 secured to the flanged head of a stud 2I6 secured to the bracket I52 as by a set screw 2I8 (Fig. 5). The width of the slot 2| 2, in a horizontal direction transverse to the screens I32 and I34 and the contactor H2, is substantially equal to the diameter of the eccentric pin portion 2I0 but is of a length greater than the diameter of this eccentric pin portion for a purpose which will presently appear.

The stud 202 i frictionally retained against inadvertent rotation by a spring strip 220 (Fig. 7) bearing at its opposite ends against the inner walls of the sleeve 204 and at an intermediate point against a reduced portion of the stud.

A set screw 222 (Figs. 4 and 7) is carried by the housing I60 and extends between shoulders formed by a second reduced portion of the stud 202 so as to retain this stud against vertical displacement. A spring pressed pin 224 mounted within the fixed plate 2I4 engages the eccentric pin portion 2I0 and frictionally retains the same in its adjusted position in the slot 2I2.

The screen I34 is adjusted relative to the screen I32 to a zero position in which the etched and therefore light opaque lines of the screens are relatively disposed as diagrammatically shown in Fig. 18 when the point of the contactor is in engagement with a true involute surface. As shown in Fig. 18, in this zero position of adjustment the etched lines 226 of the screen parhousing as by screws or the like I98. 'lhe elec- 'tro-optical or photo-electric cell I94 is preferspected to determine the operability of the lamp I68 before any test is initiated. 4

Means 200 are provided for micrometrically adjusting the housing I and hence the screen I34 relative to the screen I32. This means comprises a stud or pin 202 (Figs. 4 and 7) joumaled tially overlap the etched lines 228 of the screen I34 and cover onehalf the space between the etched lines 228. Movement of the screen I32 relative to the screen I34 in one direction therefore effects an increase in the amount of illumination or quantum of rays transmitted to the screens, whereas movement of the screen I32 in thes opposite direction effects a decrease in the amount of illumination or quantum of rays so transmitted.

In adiusting these screens to this position, the stud 202 is rotated by the knob 208 and the eccentric pin portion 2I0 in being rotated about the offset axis of the stud 202 while being held against transverse movement in the slot 2I2 causes movement of the housing I60 and the screen I34 relative to the screen I32. The elongation of the slot 2I2 prevents adjusting movement of the housing I60 and the screen I34 in a direction which could cause a variation in the spacing between this screen and the screen I32.

The bottom wall I22 of the lamp housing II9 provides the support for a spherical element or knuckle 230 (Figs. 5 and 6). The spherical element 230 engages the plunger 232 of a dial indicator 234. The dial indicator 234 is mounted upon an arm 238 which swivels about the vertical axis of the stud 2I6. which vertical axis is coincident with the center of the spherical element 230. The dial indicator may therefore be reversed from the position shown in Fig. 6 to contact the opposite side of the spherical element 230 so that the dial indicator may be moved to the most appropriate position for different types and sizes of work pieces.

The electro-optical or photo-electric cell I94 is connected to an electric recorder unit 238 (Fig. 1). This recorder unit may be of any well known conventional structure embodying an amplifier,

which. in a conventional manner, may be connected to the photo-electric cell and to a meter controlled by the amplifier. the meter providing a recording scriber or pen 246 as shown in Fig. 11. Preferably the recorder unit 226 is a Pilotel recorder marketed by a well known manufacturer of electrical instruments. Further detailed description of this recorder unit is therefore deemed unnecessary.

Means 242 (Fig. 1) are provided for connecting the auxiliary frame 66 to a mechanism 244 (Figs. 11 to 16) for feeding a sheet 246 of recording paper past the scriber 240 as the auxiliary frame 26 is shifted to cause the contactor- H2 to traverse the involute surface of a tooth of a gear being tested.

The paper feed mechanism 244 includes spaced brackets 248 (Figs. 11 and 12) for receiving a roll of paper 250 to be fed. The brackets 246 are secured to spaced supporting plates 252 pivoted as by bolts 254 to the base plate 256 of the recorder unit 238, the recorder unit being mounted on the supporting pan or base 256 secured to the main base 20.

The spaced plates 252 are main ed in vertical position (as shown in Fig. -11 by means of a spring pressed latch lever 266 pivoted to one of said plates and engageable with the fixed pin 262 secured to and projecting inwardly from one of the side walls of the housing for the recorder unit 236. The latch lever 266 projects forwardly through an opening in the front wall of a housing 264 which encloses the paper feed mechanism 244. The housing 264 is provided with a transparent window or pivoted cover 266 pivoted as at 266 for vertical movement to expose the record sheet. The housing 264 is detachably mounted on the housing for the recorder unit as by an encircling strap 216 secured to the housing 264 and adapted to overlie the meeting edges of the recorder unit housing (as shown in Fig. 11).

Paper is fed from the roll 266 by means of feed rolls 212 which are preferably provided with sprocket teeth eng the sprocket holes in the sheet of paper being fed. An arcuate guide plate 214 overlies a portion of the rolls 212 to maintain the paper in proper engagement with the sprocket teeth of these rolls. The paper is fed by these rolls onto and past a substantially horizontal paper supporting track or guide 216 secured to the spaced supporting plates 252. This track 216 extends forwardly slightLv beyond the front wall of the housing 264 and its forward,

outer end is provided with a cutting edge 216 by which a section of paper may be severed from the roll. The paper feed rolls 212 are secured toacommonshaftflljournaledinbearing brackets 262 (Fig. 15) secured to the spaced plates 252. The shaft 266 is driven through a selecflve clutch mechanism 264 (best shown in Figs. 15 and 16).

This selective clutch driving preferably comprises opposed bevel gears 266 and 266 journaled on the shaft 266 by bushings 266. The

gear266 isadaptedtobeconnectedtotheshaft 266 by a clutch spring 262 having a plurality of convolutions closely encircling or fitting about theshaft266with oneendofthesprlngbeing connected to the hub of the bevel gear 266 (as best shown in Fig. 16). The bevel'gear 266 is adaptedtobeconnectedtotheshaftflOhya:

clutch spring 264 similar to'the spring 262 but woundintheoppositedirection. Adrivingshaft 266carriesabevelgeara6meshingwithbothof thebevelgears266and266.

The driving shaft 296 is journaled in spaced bearings 366 carried by, or formed integrally with, a bracket 302 pivoted on the shaft 260 as by bushings 604.

The means 242 for connecting the auxiliary frame ill on the paper feed mechanism 244 preferably comprises a rack bar 206 (Figs. 11 to 14) detachably secured at one end to the auxiliary frame and projecting therefrom through the housing 264 into meshing engagement with a gear 306 secured to the paper feed driving shaft 266. The rack bar is slidabhr supported by one or more guide brackets Ill secured to the side walls of the housing 284 or to the spaced plates 252. A housing in for the projecting end of the rack bar 306 is secured to the far side of the housing 254.

The rack bar 366 is detachably secured to the auxiliary frame 66 by a pair of fingers or latches 3 adapted to engage the flanged end 3 of a bifurcated. bar or claw 3|! secured to the end of the rack bar. The fingers or latches 2" are pivoted to a bracket 326 secured to the auxiliary frame 86 and are normally urged by springs 222 into latching engagement with the flanged and U6 of the claw ill. A manually operable plunger 324 is mounted in the bracket 626 and is provided with a frustoconical cam 226, which, upon depression of the plunger 224, engages the latches 3 and pivots them in opposite directions to release the rack bar from the auxiliary base. A coil spring 326 normally retains the plunger in inoperative position.

It will be apparent that as the rack bar is moved to the right in Fig. 1 in response to the shifting of the auxiliary base 66, the driving shaft 296 of the paper feed mechanism will be driven in a clockwise direction as viewed from the right of Figs. 11 and 15. This clockwise rotation of the driving shaft 266 causes simultaneous rotation of the bevel gears 266 and 266 in opposite directions, the gear 268 being driven in a counterclockwise direction and the gear 266 being driven in a clockwise direction as viewed from the bottom of Fig. 15. The clockwise rotation of the gear 266 causes a tightening of the convolutions of the spring 262 about the shaft 266 and awardingly the gear 266 frictionally drives the shaft in a clockwise direction. counterclockwise rotation of the gear 266 causes an unwinding of the spring 264 and accordingly the gear 266 and the spring 264 are free to rotate relative to the shaft 266 and in a direction opposite thereto.

As the rack bar ili is moved to the left in Fig. 1,thedrivingshaft296isdriveninacounterclockwise direction as viewed fromthe right of Figs- 11 and 15. Accordingly the gear 266 is driven in a counterclockwise direction and the gear 266 is drivm in a clockwise direction as viewed from the bottom of Fig. 15. Clockwise rotation of the gear 266 causes a tightening of the convolutions of the spring 264 about the shaft 266 and the shaft is therefore frlctionaily driven in a clockwise direction bythe gear 266. Cmmtcrclockwise rotation of the gear 266 of course causes anunwindingofthespring262 andhencethe gear and spring are free to rotate relative to the shaft266andinanoppositedirectionwithrespectthereto- Itwill beseenthereforefrom this description that the paper feed rolls 212 are driven inthesamedirectlon ofthedimcflqn oi'movementoftherack barlliandtheauxiliaryframeutofeedtherecoldingpaperinthe same direction past the recording scribe:- or pen 240 as the testing contactor is moved to and fro across the involute surface being tested.

Means are provided for disconnecting the driving shaft 233 from the rack bar 306 during preliminary adjustment of the testing machine and whenever a recording of the test may not be desired. This means comprises a manually operable knob or the like 330 secured to the driving shaft 233 which for this purpose is extended outwardly beyond the front wall of the housing 264, the shaft 236 passing through an elongated slot 332 (Fig. 11) in said housing. The bracket 302 being pivoted .for movement about an axis coincident with the axis of the shaft 230, it will be apparent that upon depression of the knob 330 the driving shaft will be revolved about the axis of the driving shaft 236 and with its gear 233 will be revolved about the axis of the shaft 230 to thereby disengage the gear 303 from the rack 306. The shaft 236 is frictionally retained in its uppermost position, in which position the gear 303 meshes with the rack 306, by means of a pair of spring pressed balls or the like 334 (Fig. 12) mounted in an opening 336 (Fig. 11) at the forward end of the bracket 302.. The spring pressed balls 334 are adapted to engage opposed notches in a plate 333 slotted as at 340 to receive the forward end of the bracket 302. The plate 333 is secured as by bolts 342 to thepaper supporting track 216. Stops 344 secured to the plate 333 limit the movement of the bracket 302.

A switch 346 (Figs. 11 and 12), operable by a spring pressed plunger 343, is mounted on the plate 3 3 in a position such that the plunger will be eng ed and depressed by the bracket 302 when the knob 330 is depressed. The switch 346 in a conventional manner controls the energization of the electric recorder unit 233 so that upon the connection of the paper feed mechanism 244 and the testing instrumentalities, the recorder unit will be electrically energized.

Means are provided for raising the recording scriber or pen 240 when the supporting plates 252 of the paperfeed mechanism 244 are moved forwardly relative to the recorder unit to insert or remove a roll of paper so that the recording scriber or pen will not be injured by the paper supporting track 213 and the paper will not be marred or torn by the scriber. This means comprises a cam 350 secured to a plate 252 and adapted to engage a collar 352 carried by one of the legs of the needle lifting lever or wire 354 which forms part of the electric meter of the recorder unit, the needle or scriber of this standard meter being in two sections pivoted to each other as at 356 to permit such raising and lowering of the recording scriber or pen. A spring 353 is secured at one end to a fixed point 360 and its other end engages one of the legs of the needle lifting lever 354 so as to normally urge this lever in an upward direction (as seen in Fig. 11) whereby to raise the recording scriber. The cam 350 in engaging the collar 352 maintains the needle lifting lever in its lower position against the action of the spring 353. 7

It will be seen therefore that as the housing 264 with the spaced supporting plates 252 is moved to open position to insert or remove a roll of paper, the cam 350 will move out of engagement with the collar 352 and the spring 353, acting through the needle lifting lever 354, will move the recording scriber vertically out of engagement with the paper or its supporting track. Forward movement of the housing 254 is limited by a fixed stop 362 adapted to engage the forward edge of a supporting plate 252. In order to move the recording scriber automatically into engagement with the paper on its supporting track 216 as the housing 264 is moved to closed position, the cam350 is provided with a bevel cam face 364 adapted to engage and move the collar 352 and hence the needle lifting lever 354 downwardly against the action of the spring 353.

In order to make a test, the machine is adjusted as follows: The slide frame 22 is first adjusted relative to the main base 20 and to the supporting frame 30 to receive a cylinder or disk 42 of an external diameter equal to the base circle of the gear which is to be tested. This adjustment is accomplished by a feed screw 366 (Fig. 2) supported on the main base 20 and operated by a handwheel 363, the feed screw engaging a threaded block 310 secured to the slide frame 22. A base cylinder 42 of the appropriate size is mounted on, and clamped to, the spindle 33 and the slide frame is adjusted to bring the cylinder into engagement with the frictionally driving bar I00 carried by the supporting frame 30.

A roller bearing 312, carried by the slide bar 314 mounted on the slide frame 22, is urged by the spring 316 into engagement with the base cylinder 42 at a point diametrically opposite to the point of engagement of the bar I00 with said cylinder. A gear or other work piece having an involute tooth having been mounted between the centers 50 and 54, the two portions of the supporting frame 30 are adjusted vertically and horizontally to position the contactor I I2 of the testing instrumentality 32 in contact with the involute surface to be inspected or tested. The adjusting means 200 of the testing instrumentality 32 is then operated to adjust the screens I32 and I34 relatively into their zero position, as illustrated in Fig. 18.

The several parts of the machine are so proportioned that the point of the contactor which engages the involute tooth of the gear carried between the centers 50 and 54 lies in a plane passing through the friction face of the driving bar I00 and is therefore tangent to the base cylinder 42, which plane is therefore of course tangent to the base cylinder 42 for the particular size of gear being inspected or tested. Hence, since the gear to be tested is rotated in strict proportion to the movement of the contact point along a plane tangent to the base circle of the gear, the contactor will not be deflected about its pivot stud I33 if the surface with which it is in contact is a true involute surface.

However, if the surface being tested is not a true involute surface, the contactor will be deflected about its pivot I33 to cause the corresponding proportional movement of the screen I32 relative to the screen I34. This relative movement of the screen I32 causes a proportional variation in the amount of illumination or quantum of rays transmitted through this screen and its complementary screen I34. The quantity of illumination to which the electrooptical or photo-electric cell I34 is subjected having been varied, the current which has been generated by the cell is correspondingly varied. The current supplied to the electric recording meter of the recorder unit 233 is therefore correspondingly varied to cause the recording scriber or pen 240 to assume a new position relative to the zero or base line 313 (Fig. 17) of the recording wheel 246. The record sheet 246 being fed synchronously with the horizontal movement of the frame 30, which causes the contactor to traverse the surface being tested, the pen will describe a curve accurately representative of the pointto-point deviations of the tested surface from the true involute.

The curve shown in Fig. 17 is of course exaggerated for the purpose of illustration. For each point on the tested surface which lies on the true involute curve, the pen I will be positioned on the zero or base line 318 of the chart, but for each point lying within or beyond the true involute curve the pen wfll be positioned above or below this base line. Accordingly, the line 318 constitutes the abscissa of the recorded curve. The length of the curve along this line is proportional to the length of the surface tested and the distance of any point on the curve above or below this line corresponds to the deviation of the corresponding point of the surface tested from the true invoiute curve.

In order to correlate the degree of rotation of the base cylinder and the gear or work piece being tested with the readings on the dial indicator 234, an indicator finger m (Figs. 1 and 3) is provided. One end of the finger 380 is bifurcated by arms 382 which are adapted to frictionally engage within a peripheral recess in the upper portion of the sleeve 32. As shown in Fig. 2, the frictional engagement between the arms 382 and the sleeve 32 is suflicient to hold securely the finger 380 in place but is sufliciently impositive to permit the finger to be manually shifted for purposes of adjustment. A suitable arcuate graduated scale 3 is secured to the slide frame 22. Before a test is started the finger or pointer 380 is first moved to zero position, as indicated in Fla. 3.

It will be seen from the foregoing description that applicant has provided a compact, inexpensive, efficient and highly sensitive involute tester and recorder, in which the testing or control unit may be used for recording instruments of various types, for remote control of airplanes and ships, and as part of height and depth measuring instruments, which tester is capable of use without special training and instruction.

Changes may be made in the form, construction and arrangement of the partswithout departing from the spirit of the invention or sacriflcing any of its attendant advantages, and the right is hereby reserved to make all such changes as fairly fall within the scope of the following claims.

The invention is hereby claimed as follows: l. A tooth tester and recorder comprising a testing instrumentality including a supporting member, a tooth engaging testing contactor mounted on and shiitable relative to said supporting member and upon deviation of the tooth surface from the true tooth shape, and an electric gauge carried by said supporting member and responsive to the movement of the testing contactor relative to the supporting member, a work support member, means for shifting said work support member and said supporting member relatively to cause the testing contactor to traverse the surface of the tooth being tested, a record remote from said testing instrumentality an 'so supported as to be stationary during traversal of the tooth surface by the contactor, said recorder including an electrically operable scriber and means for feeding a record sheet to said scriber, means including an electric amplifier connected to the gauge and to the scriber of the remote recorder for causing the scriber to move across the record sheet distances which in magnitude are multiples of the movement of the testing contactor relative to the supporting member, and means connecting said sheet feeding means of the remote recorder to one of said members for operating the sheet feeding means in direct linear proportion to the extent of shifting of said one member.

2. A gear tooth tester and recorder comprising a testing instrumentality including a supporting member and a tooth engaging testing contactor mounted on and shii'table relative to said supporting member, a work support member, means for shifting said work support member and said contactor supporting member relatively to and fro to cause thetesting contactor to traverse the surface of the tooth being tested, a stationary recorder remote from said work supporting member and said contactor supporting member, said recorder including a scriber and eans for feeding a record sheet to said scri r, means 0p eratively controlled by the testing contactor for operating the scriber in direct proportion tothe extent of shifting of said testing contactor relative to its supporting member, and means connected to one of said members for driving said sheet feeding means by said one member, said driving and sheet feeding means being constructed to feed the record sheet in one direction past the scriber in amount directly proportional to the extent of shifting of said one member as the work support and the supporting member are relatively shifted to and fro.

3. A control unit comprising a support, a housing adjustably pivoted on the support, a light source and a light sensitive cell within said housing, a pair of arcuate light controlling screens concentric with the pivot axis of the housing, the first of the screens being fixed relative to the housing and the second screen being pivoted to the support for swinging about the common axis of the screens and the pivot axis of the housing, a member operatively connected to the second screen and projecting beyond the housing to receive a controlling force, and means for adiusting the housing relative to the support, said adjusting means comprising a rotatable shaft journaled in the housing and having an eccentric portion projecting beyond the housing, a fixed member having a slot to receive the eccentric portion of the shaft so that upon rotation of the shaft the housing will be shifted relative to the support to effect a zerolzing adjustment of the first screen relative to the second screen.

4. In a surface tester and recorder, means for supporting a work piece, the surface of which is to be tested, a testing instrumentality including a contactor adapted to traverse thesurface to be tested and to be deflected laterally of its direction of traversal of the surface according to the contour of said surface, an electric gauge connected to said contactor for converting the mechanical deflections of said contactor into electrical variations, shiftable means for relatively moving the work piece and the testing instrumentality to cause the surface engaging contactor to traverse the surface, a recorder remote from said gauge and said shiftable means and so supported as to be stationary during traversal of the surface by said contactor, said recorder having an electrically operable marking member, means including an electric amplifier connected to said gauge for amplifying said electrical variations and connected to said marking member of the remote recorder for moving said marking member distances which in magnitude are multiples of the mechanical deflections of said contactor, said recorder including means for feeding the record sheet past said marking member, and means connecting said moving means to said sheet feeding means of the remote recorder for driving said sheet, said driving means and said sheet feeding means being constructed to feed the sheet past the marking member in direct proportion to the extent of movement of said shiftable means.

i 5. In a surface tester and recorder, means for supporting a work piece, a surface of which is to be tested, a testing'instrumentality having a member adapted to engage said surface, shiftable means for rectilinearly moving said testing instrumentality to cause said member to traverse said surface, a recorder having a marking member operatively connected to said testing instrumentality and movable means for feeding a record sheet past said marking member, and means connecting said shiftable means to said sheet feeding means for driving said sheet feeding means in proportion to the rectilinear movement of said testing instrumentality, said driving means including a mechanism for so driving said sheet feeding means as to feed the sheet in the same direction past the marking member independently of the direction of rectilinear movement of the testing instrumentality.

6. A surface tester including a work support, a ray source, a ray controlling shutter, means including a test support and a test member shiftabLv mounted on said test support, means for moving said test support and said work support relatively to cause said test member and the surface of the work piece to be tested to move relatively along a path determined by the desired shape of said surface, said test member being shiftable relative to the test support in response to the deviation of the tested surface from its desired shape, means operatively connecting said test member to said shutter member for shifting said shutter member proportionately to the shifting of said test member relative to its support, an electro-optical cell responsive to the ray controlled by said shutter member for producing an electric current varying in proportion to the shifting of said test member relative to its support, and means operated by said varying electric current for manifesting the variations of said electric current whereby to indicate the deviations of the tested surface from its desired shape.

'1. A tooth tester including a testing member,

a support upon which said member is shiftably, mounted, means for shifting said support and the tooth relatively to cause the testing member to traverse the surface of the tooth and be shifted by said tooth surface relative to its support in response to the deviation of the tooth surface from the true tooth shape, a ray source fixed relative to said support, a ray controlling shutter device including a shiftable shutter member operatively connected to said testing member for movement relative to said support in proportion to the distance of movement of said testing member relative to the support, an electro-optical cell fixed relative to said support and responsive to the ray controlled by said device for producing an electric current varying in proportion to the movement of said testing member relative to the support, and means operated by said varying electric current for manifesting the distance of movement of the testing member relative to the support.

8. A contour testing control unit comprising a shiftable support, a light source and a light sensitive cell fixed relative to said support, a pair of light controlling screens interposed between the light source and the light sensitive cell, said screens having juxtaposed convex and concave surfaces curved about a common axis, each of said surfaces having alternate light transmitting and light interrupting portions parallel to each other and to said common axis, light opaque portions of one screen being staggered with respect to the light opaque portions of the other screen so that the light opaque portion of one screen extends from a point overlapping the light opaque portion of the other screen to a point centrally of the light transmitting portion of said other screen when said screens are in neutral position, the first of the screens being fixed relative to the support and the second screen being shiftably mounted on the support for swinging movement about the common axis to increase and decrease the light transmitted by the pair of screens in accordance with the direction and distance of movement of the second screen, a surface engaging test member mounted on said support for movement therewith and relative thereto, means for shifting said support to carry said test member across the surface to be tested along a path determined by the desired contour of the surface being tested, said testing member being shifted relative to said support upon deviation of the surface from the desired shape, means operatively connecting the test member to the second screen for swinging this screen upon movement of the test member relative to the support and in proportion to the distance of movement of said member and means controlled by the light sensitive cell for manifesting the distance of movement of the test member relative to the support.

9. A contour testing control unit comprising a shiftable support, a light source and a light sensitive cell fixed relative to said support, a pair of light controlling screens interposed between the light source and the light sensitive cell, said screens having juxtaposed convex and concave surfaces curved about a common axis, each of said surfaces having alternate light transmitting and light interrupting portions parallel to each other and to said common axis, light opaque portions of one screen being staggered with respect to the light opaque portions of the other screen so that the light opaque portion of one screen extends from a point overlapping the light opaque portion of the other screen to a point centrally of the light transmitting portion of said other screen when said screens are in neutral position, the first of the screens being fixed relative to the support and the second screen being shiftably mounted on the support for swinging movement about the common axis to increase and decrease the light transmitted by the pair of screens in accordance with the direction and distance of movement of the second screen, a surface engaging test member mounted on said support for movement therewith and relative thereto, means for shifting said support to carry said test member across the surface to be tested along a path determined by the desired contour of the surface being tested, said testing member being shifted relative to said support upon deviation of the surface from the desireds l e. means operatively connecting the test member to the second screen for swinging this screen upon movement of the test member relative to the airport and in proportion to the distance of movement of said portion member, means controlled by the light sensitive cell for manifesting the distance of movement of the test member relative to the support, and means for adjusting the shiftable support relative to the test member to adjust the first screen into neutral position relative to the second screen.

10. A contour testing control unit comprising a shiftable support, a housing pivoted on the support, a light source and a light sensitive cell fixed relative to said housing, a pair of light controlling screens interposed between the light source and the light sensitive cell, said screens having juxtaposed convex and concave surfaces concentric to the pivot-axis of the housing, each of said screens having alternate light transmitting and light interrupting portions parallel to each other and to said pivot axis, the first of the screens being fixed relative to the housing and the second screen being pivoted to the support about an axis concentric to the pivot axis of the housing, a surface engaging test member operatively connected to the second screen for swinging movement about the same axis, means for shifting the support along a predetermined path to cause this test member to traverse a path determined by the desired shape of the surface to be tested, said test member swinging relative to the support and the housing upon deviation of the tested surface from the desired shape, means for pivoting the housing relative to the support to adjust the first screen into neutral position with respect to the second screen, in which position one-half of the light transmitting portion of each screen is overlapped by a light opaque portion of the other screen, so that upon swinging of the test member relative to the housing, the quantum of light falling upon the light sensitive cell will be varied in accordance with the direction of movement of the test member and in proportion to the distance of movement of said member relative to the housing, and means operatively connected to the light sensitive cell for manifesting the direction and amount of variation of the surface tested from the desired shape.

11. A contour testing control unit comprising a shiftable support, a housing pivoted on the support, a light source and a light sensitive cell fixed relative to said housing, a pair of light controlling screens interposed between the light source and the light sensitive cell, said screens having juxtaposed convex and concave surfaces concentric to the pivot axis of the housing, each of said screens having alternate light transmitting and light interrupting portions parallel to each other and to said pivot axis, the first of the screens being fixed relative to the housing and the second screen being pivoted to the support about an axis concentric to the pivot axis of the housing, a surface engaging test member operatively connected to the second screen for swinging movement about the same axis, means for shifting the support along a predetermined path to cause this test member to traverse a path determined by the desired shape of the surface to be tested, said test member swinging relative to the support and the housing upon deviation of the tested surface from the desired shape, means for pivoting the housing relative to the support to adjust the first screen into neutral position with respect to the second screen, in which position one-half of the light transmitting of each screen is overlapped by a light opaqueportion of the other screen, so that upon swinging of the test member relative to the housing, the quantum of light falling upon the light sensitive cell will be varied in accordance with the direction of movement of the test member and in proportion to the distance of movement of said member relative to the housing and means operatively connected to the light sensitive cell for manifesting the direction and amount of variation of the surface tested from the desired shape, said adjusting means comprising a rotatable shaft joumalled in the housing and having an eccentric portion projecting beyond the housing, a member fixed to the support and having a slot to receive the eccentric portion of the shaft so that upon rotation of the shaft the housing will be adjusted about its pivot axis relative to the support.

12. In a tooth surface tester and recorder, means for supporting a work piece having a tooth the surface of which is to be tested, a testing instrumentality having a shiftable test support and a. test member shiftably mounted thereon and adapted to engage said tooth surface, means for rectilinearly moving said test support and rotating said work piece to cause said test member to traverse said surface and be deflected by the deviation of the tooth surface from a standard tooth surface, a recorder havin a marking member operatively connected to said test member and means for feeding a record sheet} past said marking member, and means connecting said moving means to said sheet feeding means for feeding said sheet in proportion to the rectilinear movement of said test support, said testing instrumentality comprising a light source and a light sensitive cell carried by said test support and a pair of light controlling screens, one of which is fixed relative to said light source in said cell and the other of which is connected to said test member for movement relative to the first screen upon deviation of the test member.

13. In a surface tester and recorder, means for supporting a work piece, the surface of which is to be tested, a testing instrumentality including a contactor adapted to traverse the surface to be tested and to be deflected laterally of its direction of traversal oi the surface according to the contour of said surface, an electric gauge connected to said contactor for converting the mechanical deflections of said contaetor into electrical variations, shiftable means for relatively moving the work piece and the testing instrumentality to cause the surface engaging contactor to traverse the surface, a recorder remote from said gauge and said shiftable means and so supported as to be stationary during traversal of the surface by said contactor, said recorder having an electrically operable marking member,

means electrically connecting said gauge to said,

marking member of the remote recorder for moving said marking member distances which in magnitude are multiples of, the mechanical deflections of said contactor, said recorder including means for feeding the record sheet past said marking member, and means connecting said .shiftable means to said sheet feeding means of the remote recorder for driving said sheet, said driving means and said sheet feeding means being constructed to feed the sheet past the marking member in direct proportion to the extent of 'movement of said shiftable means.

OUGLJESA JULES POUPITCH. 

